Files
Termix/drizzle/mysql/0072_unique_username.sql
T
ZacharyZcR e610aba0e5 fix: enforce unique usernames (#1628)
* fix: enforce unique usernames

Registration checked for a taken name, hashed the password, then
inserted, with nothing in the schema enforcing uniqueness. Concurrent
sign-ups could create two accounts with one name, after which login,
password reset, proxy login and admin lookups by username picked
between them arbitrarily.

Add a unique index on users.username for every dialect. Existing
duplicates are renamed (later rows get a -<id> suffix, the oldest keeps
the name) rather than deleted. Registration and admin user creation now
return the same 409 when the insert loses the race.

* fix: avoid username collisions during migration
2026-10-14 08:17:47 +08:00

20 lines
946 B
SQL

-- Choose an unused prefix from N + 1 disjoint prefixes for N existing users.
WITH ranked AS (
SELECT id, username,
ROW_NUMBER() OVER (ORDER BY registered_at, id) AS sequence,
ROW_NUMBER() OVER (PARTITION BY username ORDER BY registered_at, id) AS occurrence
FROM users
), candidates AS (
SELECT 0 AS candidate UNION ALL SELECT sequence FROM ranked
), available AS (
SELECT MIN(candidate) AS candidate FROM candidates
WHERE NOT EXISTS (
SELECT 1 FROM ranked WHERE username LIKE CONCAT(CONCAT('termix-recovered-', candidate, '-'), '%')
)
)
UPDATE users JOIN ranked ON ranked.id = users.id CROSS JOIN available
SET users.username = CONCAT('termix-recovered-', available.candidate, '-', ranked.sequence)
WHERE ranked.occurrence > 1;--> statement-breakpoint
ALTER TABLE `users` MODIFY COLUMN `username` varchar(255) NOT NULL;--> statement-breakpoint
ALTER TABLE `users` ADD CONSTRAINT `idx_users_username` UNIQUE(`username`);